Selected anthraquinones as potential free radical scavengers and P-glycoprotein inhibitors.

Disruption of homeostasis can increase the amount of free radicals formed during metabolic processes. This phenomenon known as oxidative stress can have numerous negative outcomes. The role of dietary antioxidants is to help the prevention of oxidative stress. We investigated free radical scavenging capacity of six structurally similar anthraquinones (alizarin, purpurin, chrysophanol, emodin, aloe-emodin and 1,3,8-trihydroxyanthraquinone) for inactivating a set of ten hydroxy and peroxy free radicals. The antioxidant capacity of anthraquinones was estimated by considering Gibbs free energy of three studied reaction mechanisms: hydrogen atom transfer (HAT), single-electron transfer followed by proton transfer (SET-PT) and sequential proton loss electron transfer (SPLET). The geometry of all participants in chemical reactions was optimized using the M06-2X/6-311++G(d,p) level of theory. Benzene, pentyl ethanoate, dimethyl sulfoxide and water were used to investigate the impact of solvent polarity on the thermodynamic feasibility of antiradical reactions. It was found that HAT and SPLET mechanisms are operative and competitive, while the SET-PT mechanism is not thermodynamically plausible. Among the studied anthraquinones, AL and PU showed the highest scavenging capacity. Their reactivity toward free radicals decreases as follows:˙OH > (CH3)3C-O˙ ≈ ˙OCH3 > CCl3-O-O˙ > PhO˙ > ˙OOH ≈ CH2[double bond, length as m-dash]CH-O-O˙ ≈ CH3-O-O˙ ≈ CH2[double bond, length as m-dash]CH-CH2-O-O˙ ≫ O2˙-. Inhibition activity of anions of the selected six anthraquinones toward P-glycoproteins was estimated using docking analysis. The obtained results suggest that all the investigated compounds are potential inhibitors of P-glycoproteins under physiological conditions, indicating them as potential protectors against patient resistance toward various anticancer drugs.

Comparative study of the effects of a small-scale trout farm on the macrozoobenthos, potamoplankton, and epilithic diatom communities.

Trout farms are one of the major sources of pollution of highland streams and rivers, which are very sensitive ecosystems otherwise scarcely influenced by human activities. A trout farm with low annual production was chosen for comparative monitoring of its effects on the macrozoobenthos, epilithic diatom, and potamoplankton communities in the receiving stream. Research was conducted every 2 months during a period of 1 year (one control point and three localities downstream from the farm). The fish farm discharge induced moderate alteration of environmental factors in the receiving watercourse, viz., significant increase of the ionized and un-ionized ammonia fraction, dissolved oxygen concentration, and biological oxygen demand. Species richness and Simpson's diversity index did not change in any of the communities. Correspondent analysis of potamoplankton community composition clearly showed trout farm effects, thereby indicating the need for reevaluation of saprobic valence values for potamoplankton species. The complete lack of influence of the trout farm discharge on the epilithic diatom community is probably due to absence of significant changes of phosphorus concentration in the receiving stream. Effects of the trout farm on the macrozoobenthos community were further characterized by 14 additional indices. The percentages of Chironomidae larvae, shredders, and total collectors; ratio of shredders to collectors; and the family biotic index are suggested as candidates for future multimetric index for measuring of trout farm influence.

Antiradical activity of catecholamines and metabolites of dopamine: theoretical and experimental study.

The importance of molecules with antiradical potency that are produced in the human body has significantly increased. Among others, neurotransmitters and their metabolites act as the first line of defense against oxidative stress in the peripheral endocrine and the central nervous systems. Dopamine (DO), epinephrine (EP), norepinephrine (NE), l-DOPA, catechol, and three metabolites of dopamine (3-methoxytyramine (3-MT), homovanillic acid (HO), and 3,4-dihydrophenylacetic acid (DOPAC)) were investigated for their antiradical potency via computational methods and DPPH assay. Density functional theory calculations were used to determine the most probable reaction mechanism based on the thermodynamic parameters. These results suggested that hydrogen atom transfer (HAT)/proton-coupled electron transfer (PCET) and sequential proton loss electron transfer (SPLET) mechanisms are preferable in polar solvents. Several techniques were employed to differentiate between HAT and PCET mechanisms via examination of the transition state structures. Kinetic studies of HAT/PCET and electron transfer (ET) reactions, the second step of SPLET, have proven that ET is much faster for an order of 105-106. Based on this, it was concluded that SPLET was the dominant mechanism for the antiradical activity towards DPPH radicals in polar solvents. The findings suggest that all the investigated molecules can be classified as excellent antiradical scavengers, except for 3-MT and homovanillic acid.

Distal venous arterialization and reperfusion injury: focus on oxidative status.

In patients with unreconstructable arterial occlusive disease distal venous arterialization (DVA) seems to be a promising option in the treatment. The goals of this prospective study were to assess clinical efficiency and possible impact of DVA on tissue damage by estimating oxidative status of patients with critical limb ischemia treated with this procedure. The subjects were 60 randomized patients: 30 were undergoing DVA and 30 were treated with antiaggregation therapy. During the mean follow-up period (6.13 ± 4.32 months for DVA vs. 6.74 ± 0.5 months for antiaggregation therapy) survival (p < 0.01), limb salvage (p < 0.001), pain relief (p < 0.001) and wound healing (p < 0.001) rates were significantly different between the two groups of patients in favor of the DVA group. Ten minutes after declamping we observed a decreasing trend in the lactate level in the blood of the deep venous system (p < 0.001). Also, on postoperative day 7 digital systolic pressure and digital-brachial index were higher than before the operation (p < 0.001). In blood samples collected immediately before and successively at 1, 3, 5 and 10 min postoperatively, prooxidative status (thiobarbituric acid reactive substances, O(2)(-), H(2)O(2) and nitric oxide) and antioxidative enzymes (superoxide dismutase, catalase and glutathione reductase) were determined spectrophotometrically. Using the nonparametric Friedman test, we noted statistically nonsignificant differences (p > 0.05) in values of both prooxidative parameters and enzymes of the antioxidative defense system, before and successively at 1, 3, 5 and 10 min after operation. These results indicate that there was no statistically significant reperfusion injury after revascularization, which could have been expected after this surgical procedure, thus confirming its validity in these patients.

Influence of resistance training on cardiorespiratory endurance and muscle power and strength in young athletes.

The purpose of this study was to investigate the influence of additional resistance training on cardiorespiratory endurance in young (15.8 ± 0.8 yrs) male basketball players. Experimental group subjects (n=23) trained twice per week for 12 weeks using a variety of general free-weight and machine exercises designed for strength acquisition, beside ongoing regular basketball training program. Control group subject (n=23) participated only in basketball training program. Oxygen uptake (VO(2max)) and related gas exchange measures were determined continuously during maximal exercise test using an automated cardiopulmonary exercise system. Muscle power of the extensors and flexors was measured by a specific computerized tensiometer. Results from the experimental group (VO(2max) 51.6 ± 5.7 ml.min(-1).kg(-1) pre vs. 50.9 ± 5.4 ml.min(-1).kg(-1) post resistance training) showed no change (p>0.05) in cardiorespiratory endurance, while muscle strength and power of main muscle groups increased significantly. These data demonstrate no negative cardiorespiratory performance effects on adding resistance training to ongoing regular training program in young athletes.

A novel method for the functionalization of gamma-irradiated single wall carbon nanotubes with DNA.

In this work we describe a novel method for highly efficient functionalization of single wall carbon nanotubes (SWCNTs) by DNA wrapping. Exposure of SWCNTs to gamma-irradiation (50 kGy) has lowered by one order of magnitude the amount of single stranded deoxyribonucleic acid (ssDNA) required for SWCNT modification. The resulting hybrids of gamma-irradiated SWCNTs and ssDNA were characterized by optical absorbance spectroscopy, Raman spectroscopy and Fourier transform infrared spectroscopy. Atomic force microscopy was used to investigate the morphology of hybrids. While gamma-irradiation in three different media has significantly improved the process of SWCNT dispersion, irradiation in ammonia was the most efficient. The gamma-irradiated SWCNTs functionalized with ssDNA were stabilized by electrostatic forces. This preliminary study suggests that gamma-irradiation can significantly improve the functionalization of SWCNTs with DNA.

[Retrocaval ureter based on a series of 16 cases]. / Uretère rétrocave: à propos de 16 cas.

INTRODUCTION AND OBJECTIVES: To analyse the postoperative results of surgical treatment for retrocaval ureter. MATERIAL AND METHODS: The authors report a retrospective clinical study of a series of 16 patients (six women and 10 men) with a mean age of 38 years (range: 15-45 years) with retrocaval ureter treated between 1975 and 2005. The mean follow-up was 18 months (range: 12 to 34 months). All patients were evaluated by the standard diagnostic protocol for the time and were treated by one of the following surgical techniques: resection of the ureter and renal pelvis to renal pelvis anastomosis; resection of the ureter and pyelo-ureteric anastomosis; resection of the ureter and oblique end-to-end uretero-ureteric anastomosis; nephrectomy. RESULTS: The mean operating time was 95 min. Late postoperative follow-up revealed two cases (13%) of ureteric stenosis at the site of the oblique end-to-end uretero-ureteric anastomosis. Surgical revision was performed in one patient with resection of the ureter and reanastomosis, while anterograde dilatation of the stenosis was performed in the other patient. The postoperative course was uneventful in both patients. All patients were reviewed at six months with a satisfactory result, corresponding to reduction of hydronephrosis and improvement of renal function. CONCLUSION: Over the last 30 years, the diagnosis of retrocaval ureter has become more reliable and less invasive. Satisfactory results can be obtained with conventional surgical management.

[Solving of complications arising during and after application self-expandible metallic stents in palliation of malignant dysphagia].

INTRODUCTION: During palliative treatment of malignant disphagia in inoperabile patients various and serious complications may occur and compromite the method of treatment if there were not solved. AIM: Goal is to present the most frequent complications due to esophageal stenting and the way of their solving. MATERIALS AND METHOD: From 1996. to 2009. in 237 patients (164 esophageal carcinoma, 33 carcinoma of the esophagogastric junction, 14 bronchial carcinoma, 7 esophagojejunal anastomosis, 9 esophageal fistulas) 245 stents have been placed (54 uncovered and 191 covered). Mean survival period was 14.7 months (ranged from 1 do 33 months). Esophageal perforation (1), stent migration (9), malignant tissue ingrowth (31) and overgrowth (24) have been revealed by barium contrast study during follow up. Perforation was solved by placing covered stent, migration by removing migrated stent endoscopically or surgically, ingrowth and overgrowth by balon dilating or restenting under the fluoroscopically guidance and control. CONCLUSION: One can expect and recognize complications regarding esophageal stenting because it is the only way for their sucsessfull treatment.

[Transcatether chemoembolization in the treatment of hepatocellular carcinoma].

UNLABELLED: The authors describe their own experience with chemoembolization as a palliation in the treatment of non resectable hepatocellular carcinoma. MATERIAL/METHODS: During period of 64 months procedure was performed in 41 patients with non resectable hepatocellular carcinoma. The combination of Lipiodol and chemotherapeutic agents were applied in a. hepatica propria and its branches via transfemorally placed catheter. Stages of neoplasms were defined by Okuda method. RESULTS: The majority of tumors (30) were classified as Grade I. Liver cirrhosis was present in 36 patients, and abnormal levels of alpha-fetoprotein were found in 68% of cases. Each of twenty nine patients had more than one chemoembolization therapy, therefore, a total of 85 treatments were carried out. CT scanning perfomed one month following the procedure revealed more than 75% of Lipiodol retention in 42% of cases, and over 90% of neoplasm necrosis was recorded in 90% of cases, while all treated patients manifested lower levels of alpha-fetoprotein. All patients survived during three and six months, respectively, while the survival rate was 68% after 18 months. No letal outcome was reported during procedure, and morbidity in relation to total number of interventions was 19%. CONCLUSION: Achieved effects of this relatively safe procedure in our series do not differ significantly from those in the literature.

[Extracorporeal percutaneous biliary-gastric "bypass" in patients with irreversible cholestasis of malignant etiology].

Authors present rarely and unusual original methods for billiary drainage type as combination of exsternal drainage and percutaneus gastrostomy. Method used in four patients with irreversibile obstruction during the last 3 years in Inteventional Radiology Dept. Clinical Center of Serbia. In all cases we have satisfactory results with survival time of about 30 days.

[How to prevent tissue overgrowth and incrustation of metal stents in the urinary tract in patients with pelvic malignancy] b ].

At the current level of stent application in urology each irreversible urostasis contraindicated for surgical therapy implies consideration of indications for metal stent insertion. Stent incrustation which leads directly into a new uroobstruction is a characteristic complication of this method. Available experience in different uroobstructive conditions has shown that very different clinical aspects of stent usage may directly determine the possibility of their incrustation. Stent incrustation may occur in the early postprocedural course or several months later. After that, prevention of stent incrustation starts with postprocedural evaluation, selection of the stent type, and it is subsequently continued by insertion technique and lasts practically permanently after the insertion (infection control, promotion of diuresis and maintenance of normal urodynamics). Authors present own experianse in clinical aplication of metal stents in uroradiology strictures for period of last 15 years.

[Algorithm for percutaneous origin of irreversible icterus ].

It is retrospective analysis of all percutaneous billiary dranage typs used in 600 patients with opstructive icterus in last 10 years.The procedure technics is analysed. It had positiv therapeutical result in about 75% cases. The most frequent complication are showed. The most coressponding percutaneous derivation algorithm is discussed. As initial method is suggested the usage of externo-internal derivation which, in dependence of the procedure, continue by internal derivation-catheteral endoprosthesys or matelic stent. The covered metalic stents usage is suggested as method of choise in metalic endoprosthesys application.

[Thoracic manifestations of gastrointestinal diseases].

Variety of gastrointestinal tract (GIT) changes that have their manifestation in thorax, disable their detailed review. Therefore, this article, represents short and overall over-view of these conditions. Standard chest x-ray can reveal esophageal disorders, herniation of abdominal organs into thorax, signs of GIT organs perforation, subphrenic abscess. Numerous diseases of intrabadominal organs of digestive tract can spread to the thorax, either per continuitatem or by lymphogenous or hemaotgenous dissemination. Therefore, chest x-ray is obliged by investigation of abdominal organs. If it is necessary additional diagnostic procedures are performed to confirm or exclude the association of lung or pleura features with GIT disorders. Above mentioned, just confirm that chest x-ray is first in algorithm of diagnostic procedures in these pathologic conditions. If there is any suspicion to conditions that require patients treatment, additional imaging methods like computerized tomography (CT), ultrasonography (US) and barium enema of digestive tract are necessary.

[Mammography in detection clinically occult breast carcinoma].

AIM: The significance of mammography in detection of nonpalpable breast cancer MATERIAL AND METHODS: This prospective study was conducted at the Institute for oncology and radiology of Serbia in Belgrade. It involved 198 asymptomatic women with performed screening mammography, 154 specimen mammography, out of wich 38 had stereotaxic mark, "ex tempore" biopsy, while 44 women had "ex tempore" biopsy and adequate surgery. RESULTS: Screening mammography revealed suspect microcalcifications in 148 cases, impaired structural tissue in 59 and focal condensation in 55 cases. Histologic examination verified breast carcinoma in 80 patients with very statistical significance of ductal type, especially comedo subvariant (p < 0.001). Pleomorphic microcalcifications smaller than 0.5 mm of grouped or segmented form are statistically very significant for malignity (p < 0.001) as well as associated microcalcifications with altered architectony and focal tissue condensation (p < 0.001). CONCLUSION: Mammography has great significance in detection of occult breast carcinoma which are not only preinvasive, but olso microinvasive and invasive. This fact leads to the neccesity of introduction of legal obligation for mammography screening, especially for women aged between 50 and 70 years.

[Functional MRI imaging in the detection of eloquent areas of the brain].

Functional magnetic resonance imaging--fMRI is a relative new magnetic resonance technique that may be used for identification of eloquent cortical areas. Gold standard for detection of eloquent areas that should be preserved subsequent to resection is a direct cortical stimulation, which is invasive and frequently difficult to be performed. On the other hand, fMRI has proved to be a promising alternative with good time and spatial resolution. The paper explains the method of the functional MR imagining, origins of the signal and its relation to the neuronal activation. fMRI technique is illustrated by the example of the motor cortex identification. Functional Magnetic Resonance Imaging--fMRI is a relatively new MR application that can be used for detection of eloquent areas of the brain. The gold standard for identifying eloquent areas of the brain to be avoided in resections is direct cortical stimulation, which is an invasive and difficult procedure. On the other hand fMRI shows great promise as noninvasive alternative to invasive brain mapping with good temporal and spatial resolution. This paper introduces the technique of fMRI, explain the origin of the signal and his connections with neural activations. An illustrative example of a motor activation study is described.

[Osteoporosis: multidisciplinary and radiologic aspects].

Osteoporosis in one of the most common diseases among the elderly individuals. Bone hardness is reduced to the critically low level. Even the smallest trauma makes previously healthy individual severely ill patient. In the USA, 1.6 million people sustain fractures due to osteoporosis each year, while approximately 14 billion dollars is spent on their treatment. The costs of osteoporosis treatment exceed the costs of prevention. The studies on the incidence, prevalence and socioeconomic aspects of osteoporosis, its prevention and treatment are expected to be carried out in our country in the future. Prevention of osteoporosis is not an individual problem, but it has wide social implications. Osteoporosis may be prevented and further loss of bone substance may be discontinued.

[Diagnosis of pericardial cysts: significance of cardiac magnetic resonance and literature review].

Pericardial cysts are uncommon and caused by an incomplete coalescence of fetal lacunae forming the pericardium. The paper presents two cases of pericardial cyst and literature review. The first is a case of a female patient with progressive dispnoa and spherical mass located in the right cardiophrenic angle on a chest x-ray. A pericardial cyst with low signal intensity was noted on T1w, high signal intensity on T2w in TSE (turbo spin echo) sequence on magnetic resonance images (MRI) which was suggestive of serous content. The patient underwent pericardial puncture and was thereafter free of symptoms. Histologic study of the cyst confirmed hydatid cyst diagnosis. Another patient is with echocardiographic evidence of cystic formation which was confirmed on MRI, with high signal intensity on SSFP (steady state free precession) sequence. The cyst was without septa and without communication with pericardial space. Since there were no significant hemodynamic changes, the patient is on regular follow up.

[CT endoscopy in urinary bladder lesions detection].

AIM: To evaluate applicability and efficacy CT virtual cystoscopy in detection of urinary bladder tumors. MATERIAL AND METHODS: During the period of 14 months, 17 patients with suspicion or present of some urinary bladder lesions has undergone CT virtual and conventional cystoscopy. After examination, all data were moved to the workstation for interactive endoluminal navigation. After that, radiologist analyzed transversal and virtual images without results of conventional cystoscopy and made conclusion. RESULTS: Results were divided according to their basic clinical application. By using this method, all lesions over 5 mm in size were revealed. In the group of patients that were followed up for urinary bladder tumors, three patients with carcinomatous lesion were revealed. Two tumors of bladder vault that were missed on transversal scan were visualized by virtual cystoscopy. Useful additional information about tumor spread was given in two patient. One tumor inside the bladder diverticulum was detected, that was not seen by conventional cystoscopy. In two patients, endoluminal origin of mass that could not be confirmed by conventional radiologic methods, was determined. CONCLUSION: CT virtual cystoscopy is useful method and technics that promise a lot, especially in following situations: a) follow up of bladder tumors; b) supplemental estimation of endoscopically hardly accessible regions; c) differential diagnosis between intravesical and exravesical lesions. Optimal estimation offers adequate bladder distension with patient positioned on the back and on the belly and interpretation as well as on transversal and virtual images.

[A new generation of urethral stents--Allium in the therapy of symptomatic prostatic enlargement of various etiology].

A number of urethral stents made of different materials, with different time of indwelling and different designs, primarily based on the vascular stent concept, have been applied in the clinical practice so far. According to the published studies, urethral stents have justified their clinical application, however with certain limitations. Within an attempt to overcome the limitations, a covered, temporary urethral stent was initially designed by Daniel Yachie and Ijko Markovi in Allium corporation from Israel. With its triangular shape, the stent is a replica of the obstructive prostatic urethral lumen. In has been applied in a series of 14 patients with lower urinary tract symptoms caused by the obstruction at the level of the prostatic urethra. The subjects were averagely aged 77.4 +/- 5.1 years. Allium prostatic stent remained in place in the patients for 4.93 +/- 3.17 months, at the average.

[64 MDCT imaging of the heart].

In the investigation of ischemic heart disease, cardiac CT imaging is the most effective non-invasive technique for exploration of the coronary arteries now. Thanks to its volume acquisition, cardiac CT is acknowledged to be the best technique for reproducible out-patient exploration not only of the coronary arteries but of all cardiac structures. Over the last 4 years, after a period of technical development and clinical validation, cardiac CT imaging has become a routine examination that is progressively finding a place alongside other types of cardiac exploration. The latest generation of faster, high-resolution devices has pushed back the limits of this technique. Not only coronography but also other modes of imaging in an increasing number of indications are progessively reduced by this complementary examination. We presented our first experiences which we had got through examinatinon of 70 patients.